Functional properties of fresh and cryopreserved carotid and femoral arteries, and of venous and synthetic grafts: comparison with arteries from normotensive and hypertensive patients

Abstract

The ideal arterial graft must share identical functional properties with the host artery. Surgical reconstruction of the common carotid artery (CA) is performed in several clinical situations, using expanded polytetrafluoroethylene prosthesis (ePTFE) or saphenous vein (SV) grafts. At date there is interest in obtaining an arterial graft that improves the results of that nowadays available. The use of a fresh or cryopreserved/defrosted artery appears as an interesting alternative. However, if the fresh and cryopreserved/defrosted arteries allow an adequate viscoelastic and functional matching with the host arteries needs to be established. The aims were to compare the viscoelastic and functional performance of: (1) conduits used in CA reconstruction (SV and ePTFE) with those of the fresh and cryopreserved/ defrosted CA and femoral arteries (FA), and (2) normotensive and hypertensive patients' arteries with those of the arterial substitutes in vitro analyzed. Pressure, diameter and wall thickness of the CA were recorded in 15 normotensive and 15 hypertensive patients (in vivo studies), and in SV, fresh and cryopreserved/defrosted CA and FA (obtained from 15 donors), and ePTFE segments (in vitro studies). From stress-strain relationship we calculated elastic and viscous modulus, and the characteristic impedance. The local buffer and conduit functions were quantified as the viscous/elastic quotient and the inverse of the characteristic impedance. Fresh and cryopreserved/defrosted CA and FA were more alike, both in viscoelastic and functional levels, respect to normotensive and hypertensive patients' arteries, than the ePTFE and SV grafts. CA and FA cryografts could be considered an important alternative for carotid reconstruction.